Presser-foot-locking mechanism for sewing-machines.



Patented Aug. 5, |902.l

H. A. KLEMM. A PRESSER FO0T LOCKING MECHANISM FOB SEWING MACHINES. n

rApplicaion med sept. 9, 1901.)

(no model.)

F|Gr.2.

lNVE TOR WITNESSES:

UNITED STATES PATENTr OFFICE."

' HERMANN A. KLEMM, oE NEw YORK, N; Y. f

PREssER-FooT-LOCKING MECHANISM FOR" SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 706,068, dated August 5, 1902. Application led September 9, 1901. Serial No. 74,727. (No model.)

a position in which-the presser-foot willcol-` lide with it in shifting either way to prevent damage to the looper, as hereinafter described,-v

reference being made to the accompanying drawings, in which- Figure 1 is a front elevation of some parts and vertical sections of other parts of a machine provided With my improved automatic presser-locking device. Fig. 2 is an elevation of the same as seen looking from the left hand of the view represented in Fig. l, with the throat-plate and parts of the bed-plate in vertical section. Fig. 3 is a detail in vertical section of the head of the supporting-arm parallel with but in a plane behind the plane of the section of Fig. I and indicated by the linel 2 2 of Fig. 2.

A represents the head of the stationary arm,in which the needle-bar a and the presser b are mounted, as usual.

c represents the presser-foot; ,the throatplate; e, the bed-plate, and f the feed-dog.

g represents the oscillating hook for bringing the needle-thread loops up -to the'reciprocating looper h,and t' represents the needle. The arrangements of the hook and loopery are such that the looper reaches over the presser-foot in the forwardpart of its rangel in operation or under it if the machine be turned when the presser is up,wherefore there is danger of breaking the looper by shiftingy the presser-foot while the looper may happen to rest over or under the presser-foot, which it is the purpose of my invention'to preventby automatic action of the'machine through a locking device that will eiectually prevent' shifting the presser-foot by said presser-lifterI while the looper is over or under the pressert foot, but will not obstruct the shifting While the looper rests in any position clear of the range of the presser-foot.

Various contrivances of apparatus may be .employed for this purpose; but in this example of my inventionI represent a presser-lifting lever j, pivoted at 7c and suitably adapted for liftingthe presser, as usual, by taking effect onarm Z of the collarm, clamped on the Vpresser-bar,'in which lever If'provide a hole mwhich when the lever is in the position allowing the presser to be in the working posi tion coincides with a hole 0 in the head A, in which a rod p is arranged, which extends rearward and is connected to a short arm q (dotted in Fig. l) of a rock-shaft 1', mounted Aon the standard s and having a longer arm u, kto which the looper-carrying staii' 'u is connected for being operated, so that said rod p and the looper-staff reciprocate in unison, and the arrangements and adjustments are such that said rod p enters hole n of lever j when the point of the looper advances over the presser-foot and thus locks the presser-lifter, 'and when the point of the looper retires from over the presser-foot said rod retires from the hole in the lifter and leaves it free to be actuated forlifting the presser-foot, and ifY after liftingthe presser the machine be turned by hand so that the looper reaches under` the presser-foot, the rod p being at the same time shifted forward under the lever j, as Willlbe seen in FigL 2, will lock said lever and thus prevent the presser from being shifted down and in that way colliding with the looper. 'Thus the operator is estopped from lifting the .presser'when it would be injurious to the looper. l

The contrivances of the apparatus may of course be modified in various Ways, and I do not limit myself to the particular contrivances lherein represented.

The means of operating the rock-shaft?" are indicated. by the connecting-rod w and arm 00, and the means of operating the hook are indicated by the reciprocating toothed rack y and the pinion z; but they form no part of .the invention claimed and need not be further described.

What I claim as my invention is- IOO and presser-lifter, said looper having means of the range of the presser-foot, means for' automatically locking the presser-foot when the looper is Within the range of said presserfoot and unlocking the same when the looper 15 is out of the range of the presser-foot.

Signed at New York city this 20th day of August, 1901.

Y HERMANN A. KLEMM. Witnesses:

A. P. THAYER, C. SEDGWICK. 

